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Finding the Fourth Proportional to 231.98, 320.09 and 138.71

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Solution

The fourth proportional to 231.98, 320.09 and 138.71 is: 191.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    231.98 : 320.09 = 138.71 : x
  2. Step 2: Convert to fraction form
    231.98/320.09 = 138.71/x
  3. Step 3: Cross multiply
    231.98x = 320.09 × 138.71
  4. Step 4: Simplify right side
    231.98x = 44,400.03
  5. Step 5: Solve for x
    x = 44,400.03/231.98
  6. Step 6: Final answer
    x = 191.40

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.